🤖 MCP Server mytool3

A lightweight Model Context Protocol (MCP) server that provides a bridge between Claude AI and your local Python environment.

🌟 Overview

• mytool3 is a proof-of-concept MCP server built to demonstrate the seamless integration of local Python execution with Claude Desktop.

• It allows Claude to "step out" of its sandbox and interact with your machine via a standard tool interface.

📁 Project Structure

mcp_gen/
├── .venv/                 
├── mcpgen/                 # generator logic
├── ├── __init__.py
|   ├── cli.py
├   ├── generator.py              
│   ├── mytool3/            # MCP server       
│   │   ├── __init__.py   
│   │   ├── server.py      
│   │   └── mcp.json                      
├── .gitignore             
├── README.md              
└── pyproject.toml

⚒️ Features Standard Discovery:

• Automatically announces its tools to Claude via the list_tools protocol.

• Synchronous Execution: Uses stdio transport for high-speed, local communication.

• Adaptive Integration: Fully compatible with the Claude Desktop interface.

⚒️ Installation & Setup

• Environment Initialization Standardize the local environment using a virtual environment to isolate the MCP dependencies.

# Clone the repository
git clone https://github.com/reory/mytool3.git
cd mytool3

Create and activate virtual environment

python -m venv .venv
source .venv/bin/activate  # Automation for Mac/Linux
**OR: .venv\Scripts\activate (Windows)**

Related MCP server: My UV MCP Server

Upgrade core tooling

pip install --upgrade pip setuptools

• Dependency Resolution This project leverages the fastmcp SDK for streamlined protocol handling.

# Install required MCP packages
pip install fastmcp mcp

Verify installation

python -c "import fastmcp; print(f'FastMCP version: {fastmcp.version}')"

• Service Registration (Claude Desktop) To hook the server into the Claude Desktop runtime, inject the absolute paths into your local configuration. Command-line shortcut (PowerShell): PowerShell

Open the specific MSIX config path for the Windows Store version

• notepad "$env:LOCALAPPDATA\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\claude_desktop_config.json" JSON Payload:

JSON { "mcpServers": { "mytool3": { "command": "C:\Absolute\Path\To\.venv\Scripts\python.exe", "args": ["C:\Absolute\Path\To\mcpgen\mytool3\server.py"] } } }

🧪 Development Workflow

Manual Protocol Test Before testing in the Claude UI, ensure the server initiates the stdio transport without Python exceptions:

# Set unbuffered mode to prevent pipe-hangs
export PYTHONUNBUFFERED=1
python mcpgen/mytool3/server.py

• Hot-Reloading (Optional) If iterating on tool logic, use the fastmcp dev-tools for immediate feedback:

fastmcp dev mcpgen/mytool3/server.py

🔧 Tools Available

⚠️ Troubleshooting

• Silent Failures: If the "Running" badge is blue but no tools appear, ensure your server.py is returning CallToolResult and not CallToolRequest.

• The Ghost Sandbox: If changes to the code aren't reflecting, use Task Manager to End Task on all Claude processes to force a config reload.

• Import Errors: Ensure you run pip install mcp specifically for the Python version defined in your command path.

• It specifically calls out the 2026 UI features like the "Connectors" menu, which didn't exist in older versions of the app.Path Accuracy: It preserves that long, annoying "Packages" path we found—this is the #1 thing that trips people up.

• Code Logic: It warns about the Result vs Request trap we just solved.

🛣️ Roadmap Features

• Persistent Memory (SQLite Integration) Goal: Give Claude a "long-term memory" that persists across different chat sessions.

• File System Sentinel (Local I/O) Goal: Allow Claude to safely inspect and summarize local directory structures.

• Web Research Bridge (Playwright/Scraper) Goal: Enable Claude to fetch real-time data from sites without official APIs (like documentation pages).

📁 Notes

• This was challenging to build as FastMcp is a new library in python and the documentation is new and still evolving. I had to cross reference documents from a few different sources. FastMcp

• Built By Roy Peters Contact 😁